1. Field of the Invention
The present invention relates to a printer and a power controlling method for the same, and more particularly, to a printer capable of reducing power consumption by gradually reducing power supply to the printer according to the duration for which the printer is not used, and a power controlling method for the same.
2. Description of the Related Art
In general, a printer has a controller for controlling the processing of received print data and the overall printer system, an input device which outputs a signal to the controller according to the operation of a function key, a print engine substantially charging a print job for printing on a sheet of paper while controlled by the controller, and a power supply unit for supplying electric power.
The print engine includes devices which must be heated at a constant temperature so as to enable a normal print job to be done, such as a transfer device for transferring and fixing a toner image formed on a photosensitive medium onto a sheet of paper. Therefore, in order to keep the print engine ready to do a print job, the transfer device must be continuously supplied with electric power required for heating the transfer device.
However, when the printer is not used for a long time while in the on state, such continuous supply of power causes unnecessary power consumption. Taking this fact into account, most printers employ a power saving mode so as to reduce power consumption when the printer is not used for a predetermined period of time. In the power saving mode, the power supply to a print engine is not completely shut off, and a level of power less than that required for doing a print job is supplied to the print engine. For example, the constant temperature of the transfer device is 100.degree. C. in a ready-to-print mode in which a print job can be done, and the constant temperature of the transfer device can be maintained at 50.degree. C. in a power saving mode.
However, since the printer still consumes power of several tens of watts even in the conventional power saving mode for saving power, power consumption may be large when the printer is not used for a long time while in the on state.
On the other hand, since the power mode of a conventional printer cannot be changed by a user, there is a disadvantage in that the power consumed when the printer is not used cannot be appropriately controlled.